Biosorption of Cu(2+), Pb(2+) and Cr(6+) by a novel exopolysaccharide from Arthrobacter ps-5.

The biosorption behaviors and mechanisms for Cu(2+), Pb(2+) and Cr(6+) by a novel exopolysaccharide (EPS) from Arthrobacter ps-5 have been studied in the paper. The influences of EPS concentration, solution pH and ionic strength on adsorption property were investigated. The EPS showed strong biosorption capability, up to 169.15mg/g of Cu(2+), 216.09mg/g of Pb(2+) and 84.47mg/g of Cr(6+), respectively. With the additional concentration of Ca(2+) and K(+) increased, the biosorption ability on Cu(2+), Pb(2+) and Cr(6+) decreased significantly and followed the order of K(+)<Ca(2+). Infrared spectrometry analysis demonstrated that the groups of OH, CO, COC and COC of the EPS involved in metal biosorption process were the main functional groups for binding metal ions.